VB.Net Tutorial/Class Module/Property

Change value in Property getter

<source lang="vbnet">Imports System Module Test

 Sub Main()
   Dim p as Point = New Point()
   Console.WriteLine("(" & p.X & "," & p.Y & ")") 
   Try
     p.X = -100
     p.Y = -100
   Catch e as ArgumentOutOfRangeException
     Console.WriteLine(e.Message)
   End Try
   Console.WriteLine("(" & p.X & "," & p.Y & ")") 
 End Sub

End Module Public Class Point

 Private yCoord as Integer
 Private xCoord as Integer
   Public Property X as Integer
     Get
       Return(xCoord * 2) 
     End Get
     Set(ByVal Value as Integer)
       xCoord = Value
     End Set
   End Property
 
 Public Property Y as Integer
   Get
     Return(yCoord)
   End Get
   Set(ByVal Value as Integer)
     yCoord = Value
   End Set
 End Property

End Class</source>

(0,0)
(-200,-100)

Class with a property that performs validation

<source lang="vbnet">Module YourClassTest

  Sub Main()
     Dim obj1 As New YourClass("AAA")
     Dim obj2 As New YourClass("SSSSSSSSSSSSSSSSSSs")
     Console.WriteLine(obj1.YourName)
     Console.WriteLine(obj2.YourName)
     obj1.YourName = "asdfasdfasdfasdf"
     Console.WriteLine("obj1"s course name is: " & obj1.YourName)
     Console.WriteLine("obj2"s course name is: " & obj2.YourName)
  End Sub " Main

End Module

Public Class YourClass

  Private yourNameValue As String " course name for this YourClass
  Public Sub New(ByVal name As String)
     YourName = name " validate and store course name
  End Sub " New
  Public Property YourName() As String
     Get " retrieve yourNameValue
        Return yourNameValue
     End Get
     Set(ByVal value As String) 
        If value.Length <= 5 Then " if value has 5 or fewer characters
           yourNameValue = value " store the course name in the object
        End If
        If value.Length > 5 Then " if value has more than 5 characters
           yourNameValue = value.Substring(0, 5)
           Console.WriteLine("Name """ & value & """ exceeds maximum length (5).")
           Console.WriteLine("Limiting name to first 5 characters." & vbCrLf)
        End If
     End Set
  End Property " YourName
  Public Sub DisplayMessage()
     Console.WriteLine("Welcome to " & YourName & "!")
  End Sub " DisplayMessage

End Class</source>

Name "SSSSSSSSSSSSSSSSSSs" exceeds maximum length (5).
Limiting name to first 5 characters.
AAA
SSSSS
Name "asdfasdfasdfasdf" exceeds maximum length (5).
Limiting name to first 5 characters.
obj1"s course name is: asdfa
obj2"s course name is: SSSSS

Convert data type in property set

<source lang="vbnet">Public Class YourClass

 Private MyState as String = "DEFAULT"
 Public Property State As String
   Get
     Return MyState
   End Get
   Set(Value As String)
     MyState = Value
   End Set
 End Property
 

End Class Module Test

 Sub Main()
   Dim C As New YourClass()
   Console.WriteLine(C.State)
   
   C.State = 5
   
   Console.WriteLine(C.State)
   
 End Sub

End Module</source>

DEFAULT
5

Default Property

<source lang="vbnet">Imports System Imports System.Collections Class EmployeeList

 Private mEmployees As Hashtable
 Public Sub New()
   mEmployees = New Hashtable()
 End Sub
 Public Default Property Employee(ByVal ID As Integer) As Employee
   Get
     Dim theObject As Object
     theObject = mEmployees(ID)
     Return CType(theObject, Employee)
   End Get
   Set(ByVal Value As Employee)
     mEmployees(ID) = Value
   End Set
 End Property

End Class Class Employee

 Private mName As String
 Private mWage As Double
 Private mID As Integer
 Public Sub New(ByVal name As String, _
                ByVal wage As Double, _
                ByVal id As Integer)
   mName = name
   mWage = wage
   mID = id
 End Sub
 Public Property Name() As String
   Get
     Return mName
   End Get
   Set(ByVal Value As String)
     mName = Value
   End Set
 End Property
 Public ReadOnly Property Wage() As Double
   Get
     Return mWage
   End Get
 End Property
 Public ReadOnly Property ID() As Integer
   Get
     Return mID
   End Get
 End Property
 Public Sub PayRise(ByVal amount As Double)
   mWage += amount
 End Sub
 Public Overrides Function ToString() As String
   Return "[" & mID & "] " & mName & " " & mWage
 End Function

End Class

Module Test

 Sub Main()
   Dim employer As New EmployeeList()
   employer.Employee(1) = New Employee("A", 25000, 1)
   employer.Employee(2) = New Employee("J", 35000, 2)
   employer.Employee(3) = New Employee("T", 17000, 3)
   employer.Employee(4) = New Employee("E", 16500, 4)
   Dim ID As Integer
   ID = 2
   Dim who As Employee
   who = employer.Employee(ID)
   If who Is Nothing Then
     Console.WriteLine("Unrecognized ID: {0}", ID)
   Else
     Console.WriteLine("Employee details: {0}", who)
   End If
 End Sub

End Module</source>

Employee details: [2] J 35000

Define and use a Property

<source lang="vbnet">Option Strict On

Imports System
Public Class Cat
   Private mWeight As Integer
   Public Sub New(ByVal weight As Integer)
      mWeight = weight
   End Sub
   Public Property Weight( ) As Integer
      Get
         Return mWeight
      End Get
      Set(ByVal Value As Integer)
         mWeight = Value
      End Set
   End Property
   Public Overrides Function ToString( ) As String
      Return mWeight.ToString( )
   End Function
End Class
Module Module1
   Sub Main( )
      Dim theVariable As New Cat(5)
      Console.WriteLine("In Run. theVariable: {0}",theVariable)
      Doubler(theVariable)
      Console.WriteLine("Back in Run. theVariable: {0}",theVariable)
   End Sub
   Public Sub Doubler(ByVal param As Cat)
      Console.WriteLine("In Method1. Received param: {0}",param)
      param.Weight = param.Weight * 2
      Console.WriteLine("Updated param. Returning new value: {0}",param)
   End Sub
End Module</source>

In Run. theVariable: 5
In Method1. Received param: 5
Updated param. Returning new value: 10
Back in Run. theVariable: 10

Do calculation in Property getter

<source lang="vbnet">Imports System Imports System.Data.OleDb Imports System.ruponentModel.ruponent Class Employee

 Private MName As String
 Private MDob As DateTime
 Private MCompany As String
 Public Sub New(ByVal name As String, ByVal dob As DateTime)
   MName = name
   MDob = dob
   MCompany = "ABC"
 End Sub
 Public Property Name() As String
   Get
     Return MName
   End Get
   Set(ByVal Value As String)
     MName = Value
   End Set
 End Property
 Public ReadOnly Property Age() As Integer
   Get
     Dim today As DateTime = DateTime.Now
     Dim Years As Integer = DateTime.Now.Year - mDob.Year
     If (today.Month < MDob.Month) Or _
        (today.Month = MDob.Month And _ 
         today.Day < MDob.Day) Then
       Years -= 1
     End If
     Return years
   End Get
 End Property

End Class Module Test

 Sub Main()
   Dim AEmployee As New Employee("A", New DateTime(1964, 12, 3))
   Console.WriteLine("{0} is {1}", AEmployee.Name, AEmployee.Age)
 End Sub

End Module</source>

A is 42

Do data check in property set

<source lang="vbnet">public class Test

  public Shared Sub Main
       Dim objMyObject As YourClass
       objMyObject = New YourClass()
       Console.WriteLine(objMyObject.AddTwoNumbers(1, 2))
       objMyObject = Nothing
  End Sub

End Class Public Class YourClass

   Private m_intHeight As Integer
   
   Public Property Height() As Integer
       Get
           Return m_intHeight
       End Get
       Set(ByVal value As Integer)
           If m_intHeight < 10 Then Exit Property
           m_intHeight = value
       End Set
   End Property
   Public Function AddTwoNumbers(ByVal intNumber1 As Integer, _
                                 ByVal intNumber2 As Integer) As Long
       AddTwoNumbers = intNumber1 + intNumber2
   End Function

End Class</source>

3

Friend Property

<source lang="vbnet">Imports System Module Test

 Sub Main()
   Dim acct As New Account()
   Console.WriteLine(acct.AccountHolder)
   Dim cAcct As New CheckingAccount()
   Console.WriteLine(cAcct.AccountHolder)
 End Sub

End Module Public Class CheckingAccount

 Inherits Account
 Sub New()
   MyBase.New
   Console.WriteLine(MyBase.retrieved) 
   Console.WriteLine(MyBase.AccountHolder)
 End Sub

End Class Public Class Account

 Protected retrieved As DateTime
 Private acctHolder As String
 
 Public Sub New()
   retrieved = DateTime.Now()
   acctHolder = "DEFAULT"
 End Sub
 
 Friend Property AccountHolder As String
   Get
     Return acctHolder
   End Get
   Set(ByVal Value As String) 
     acctHolder = Value
   End Set
 End Property

End Class</source>

DEFAULT
11/05/2007 12:22:44 PM
DEFAULT
DEFAULT

Loop through two dimensional array with GetUpperBound and GetLowerBound

<source lang="vbnet">Imports System.Collections public class Test

  public Shared Sub Main
       Dim i As Integer
       Dim j As Integer
              Dim myArray4(2, 2) As Object             "2 dimensional array with 9 elements
              For i = myArray4.GetLowerBound(0) To myArray4.GetUpperBound(0)
                      For j = myArray4.GetLowerBound(1) To myArray4.GetUpperBound(1)
               myArray4(i, j) = i + j
                      Next
              Next
              For i = myArray4.GetLowerBound(0) To myArray4.GetUpperBound(0)
                      For j = myArray4.GetLowerBound(1) To myArray4.GetUpperBound(1)
                              Console.WriteLine(myArray4(i, j))
                      Next
              Next
  End Sub

End class</source>

0
1
2
1
2
3
2
3
4

MultiKey Properties

<source lang="vbnet">Imports System Imports System.Collections Class Employee

 Private MName As String
 Private MWage As Double
 Public Sub New(ByVal Name As String, ByVal Wage As Double)
   MName = Name
   MWage = Wage
 End Sub
 Public Property Name() As String
   Get
     Return MName
   End Get
   Set(ByVal Value As String)
     MName = Value
   End Set
 End Property
 Public ReadOnly Property Wage() As Double
   Get
     Return MWage
   End Get
 End Property
 Public Sub PayRaise(ByVal Amount As Double)
   MWage += Amount
 End Sub
 Public Overrides Function ToString() As String
   Return MName & " " & MWage
 End Function

End Class Class EmployeeList

 Private MEmployees As Hashtable
 Public Sub New()
   MEmployees = New Hashtable()
 End Sub
 Public Property Employee(ByVal Location As String, ByVal ID As Integer) As Employee
   Get
     Dim Key As String = Location + ID.ToString()
     Return MEmployees(Key)
   End Get
   Set(ByVal Value As Employee)
     Dim Key As String = Location + ID.ToString()
     MEmployees(Key) = Value
   End Set
 End Property

End Class Module Test

 Sub Main()
   Dim EmployeeList As New EmployeeList()
   EmployeeList.Employee("A", 1) = New Employee("S", 2)
   EmployeeList.Employee("B", 2) = New Employee("C", 3)
   EmployeeList.Employee("C", 3) = New Employee("B", 1)
   EmployeeList.Employee("D", 4) = New Employee("A", 1)
   Dim Who As Employee
   Who = EmployeeList.Employee("Boston", 200)
   Console.WriteLine("{0}", Who)
   Who = EmployeeList.Employee("Geneva", 200)
   Console.WriteLine("{0}", Who)
 End Sub

End Module</source>

Overloaded Properties

<source lang="vbnet">Imports System Imports System.Collections Class Employee

 Public Name As String
 Public Wage As Double
 Public ID As Integer
 Public Sub New(ByVal N As String, ByVal W As Double, ByVal I As Integer)
    Name = N
    Wage = W
    ID = I
 End Sub
 Public Sub PayRaise(ByVal Amount As Double)
   Wage += Amount
 End Sub

 Public Overrides Function ToString() As String
   Return "[" & ID & "]" & " " & Name & " " & Wage
 End Function

End Class Class EmployeeList

 Private idTable As Hashtable
 Private nameTable As Hashtable
 
 Public Sub New()
   idTable = New Hashtable()
   nameTable = New Hashtable()
 End Sub
 Public Property Employee(ByVal ID As Integer) As Employee
   Get
     Return idTable(ID)
   End Get
   Set(ByVal Value As Employee)
     idTable(ID) = Value
   End Set
 End Property
 Public Property Employee(ByVal Name As String) As Employee
   Get
     Return nameTable(name)
   End Get
   Set(ByVal Value As Employee)
     nameTable(Name) = Value
   End Set
 End Property

End Class Module Test

 Sub Main()
   Dim EmployeeList As New EmployeeList()
   EmployeeList.Employee(1) = New Employee("A", 250, 100)
   EmployeeList.Employee(2) = New Employee("B", 350, 200)
   EmployeeList.Employee(3) = New Employee("C", 170, 300)
   EmployeeList.Employee(4) = New Employee("D", 165, 400)
   EmployeeList.Employee("N") = New Employee("N", 50000, 500)
   EmployeeList.Employee("C") = New Employee("C", 60000, 600)
   Dim ID As Integer = 1
   Dim Who As Employee
   Who = EmployeeList.Employee(ID)
   If Who Is Nothing Then
     Console.WriteLine("Unrecognized ID: {0}", ID)
   Else
     Console.WriteLine("Employee details: {0}", Who)
   End If
   Dim Name As String = "N"
   Who = EmployeeList.Employee(Name)
   If Who Is Nothing Then
     Console.WriteLine("Unrecognized name: {0}", Name)
   Else
     Console.WriteLine("Employee details: {0}", Who)
   End If
 End Sub

End Module</source>

Employee details: [100] A 250
Employee details: [500] N 50000

Properties with Getter and Setter

<source lang="vbnet">Public Class Tester

   Public Shared Sub Main
     Dim time As New CTime3()
     " add one second
     time.Second = (time.Second + 1) Mod 60
     " add one minute if 60 seconds have passed
     If time.Second = 0 Then
        time.Minute = (time.Minute + 1) Mod 60
        " add one hour if 60 minutes have passed
        If time.Minute = 0 Then
           time.Hour = (time.Hour + 1) Mod 24
        End If
     End If
     time.Hour = 1
     time.Minute = 2
     time.Second = 3
     Console.WriteLine("Hour: " & time.Hour & "; Minute: " & _
        time.Minute & "; Second: " & time.Second)
   End Sub

End Class Class CTime3

  Inherits Object
  Private mHour As Integer
  Private mMinute As Integer
  Private mSecond As Integer
  Public Sub New()
  End Sub " New
  " property Hour
  Public Property Hour() As Integer
     " return mHour value
     Get
        Return mHour
     End Get
     " set mHour value
     Set(ByVal value As Integer)
        If (value >= 0 AndAlso value < 24) Then
           mHour = value
        Else
           mHour = 0
        End If
     End Set
  End Property " Hour
  " property Minute
  Public Property Minute() As Integer
     " return mMinute value
     Get
        Return mMinute
     End Get
     " set mMinute value
     Set(ByVal value As Integer)
        If (value >= 0 AndAlso value < 60) Then
           mMinute = value
        Else
           mMinute = 0
        End If
     End Set
  End Property " Minute
  " property Second
  Public Property Second() As Integer
     " return mSecond value
     Get
        Return mSecond
     End Get
     " set mSecond value
     Set(ByVal value As Integer)
        If (value >= 0 AndAlso value < 60) Then
           mSecond = value
        Else
           mSecond = 0
        End If
     End Set
  End Property " Second

End Class</source>

Hour: 1; Minute: 2; Second: 3

Readable and Writable

<source lang="vbnet">Imports System Class Employee

 Private MName As String
 Private MDob As DateTime
 Private MEmailAlias As String
 Public Sub New(ByVal Name As String, ByVal Dob As DateTime)
   MName = Name
   MDob = Dob
 End Sub
 Public Property Name() As String
   Get
     Return MName
   End Get
   Set(ByVal Value As String)
     MName = Value
   End Set
 End Property
 Public ReadOnly Property Brithday() As DateTime
   Get
     Return MDob
   End Get
 End Property
 Public WriteOnly Property EmailAlias() As String
   Set(ByVal Value As String)
     MEmailAlias = Value
   End Set
 End Property
 Public ReadOnly Property EmailAddress() As String
   Get
     Return MEmailAlias & "@a.ru"
   End Get
 End Property

End Class Module ReadableAndWritable

 Sub Main()
   Dim emp As New Employee("T", New DateTime(1997, 7, 2))
   emp.Name = "T"
   Console.WriteLine("Name: {0}", emp.Name)
   Console.WriteLine("Date of birth: {0}", emp.Brithday.ToLongDateString)
   emp.EmailAlias = "AAA"
   Console.WriteLine("Email address: {0}", emp.EmailAddress)
 End Sub

End Module</source>

Name: T
Date of birth: July 2, 1997
Email address: AAA@a.ru

ReadOnly property

<source lang="vbnet">Option Strict On Public Class YourClass

  Private yourName As String
  Private yourNumber As Decimal
  Public Sub New(breed As String)
     yourName = breed
  End Sub
  Public ReadOnly Property Name() As String
     Get
        Return yourName
     End Get
  End Property
  Public Property Number() As Decimal
     Get
        Return yourNumber
     End Get
     Set
        yourNumber = CDec(value)
     End Set
  End Property
  Public Sub ShowInfo()
     Console.WriteLine("This " & yourName & " weighs " & yourNumber & " pounds.")
  End Sub

End Class Public Class Tester

  Public Shared Sub Main()
     Dim mal As New YourClass("A")
     mal.Number = 130
     ChangeYourClassInfo(mal)
     mal.ShowInfo
     CompletelyChangeYourClassInfo(mal)
     mal.ShowInfo
  End Sub
  Public Shared Sub ChangeYourClassInfo(ByVal aYourClass As YourClass)
     aYourClass.Number = 125
  End Sub
  Public Shared Sub CompletelyChangeYourClassInfo(ByVal aYourClass As YourClass)
     Dim newf As New YourClass("Newfoundland")
     aYourClass = newf
  End Sub

End Class</source>

This A weighs 125 pounds.
This A weighs 125 pounds.

Shared Properties

<source lang="vbnet">Imports System Class Person

 Private Shared MDomain As String
 Private Name As String
 Private Birthday As DateTime
 Private EmailAlias As String
 Public Shared Property Domain() As String
   Get
     Return MDomain
   End Get
   Set(ByVal Value As String)
     MDomain = Value
   End Set
 End Property
 Public Sub New(ByVal N As String, ByVal Dob As DateTime)
   Name = N
   Birthday = Dob
 End Sub

End Class Module Test

 Sub Main()
   Dim APerson As New Person("P", New DateTime(1997, 7, 2))
   Person.Domain = "My.ru"
 End Sub

End Module</source>

Shared variable and Shared Property

<source lang="vbnet">Module Tester

  Sub Main()
     Console.WriteLine("Employees before instantiation: " & _
        Employee.Count)
     Dim employee1 As Employee = New Employee("S", "B")
     Dim employee2 As Employee = New Employee("B", "J")
     Console.WriteLine("Employee.Count: " & Employee.Count)
     employee1 = Nothing
     employee2 = Nothing
     System.GC.Collect() " request garbage collection
     
     Console.WriteLine("Employee.Count: " & Employee.Count)
     
  End Sub " Main

End Module Class Employee

  Inherits Object
  Private mFirstName As String
  Private mLastName As String
  Private Shared mCount As Integer
  Public Sub New(ByVal firstNameValue As String, _
     ByVal lastNameValue As String)
     mFirstName = firstNameValue
     mLastName = lastNameValue
     mCount += 1 
     Console.WriteLine _
        ("Employee object constructor: " & mFirstName & _
        " " & mLastName)
  End Sub " New
  Protected Overrides Sub Finalize()
     mCount -= 1 " decrement mCount, resulting in one fewer object
     Console.WriteLine _
        ("Employee object finalizer: " & mFirstName & _
        " " & mLastName & "; count = " & mCount)
  End Sub " Finalize
  Public ReadOnly Property FirstName() As String
     Get
        Return mFirstName
     End Get
  End Property " FirstName
  " return last name
  Public ReadOnly Property LastName() As String
     Get
        Return mLastName
     End Get
  End Property " LastName
  " property Count
  Public Shared ReadOnly Property Count() As Integer
     Get
        Return mCount
     End Get
  End Property " Count

End Class</source>

Employees before instantiation: 0
Employee object constructor: S B
Employee object constructor: B J
Employee.Count: 2
Employee object finalizer: B J; count = 1
Employee object finalizer: S B; count = 0
Employee.Count: 0

Single Indexed Property

<source lang="vbnet">Imports System Imports System.Collections Class Employee

 Public Name As String
 Public Wage As Double
 Public Sub New(ByVal N As String, ByVal W As Double)
   Name = N
   Wage = W
 End Sub
   Public Sub PayRaise(ByVal Amount As Double)
       Wage += Amount
   End Sub
   Public Overrides Function ToString() As String
       Return Name & " " & Wage
   End Function

End Class Class Employer

 Private MEmployees As Hashtable
 Public Sub New()
   MEmployees = New Hashtable()
 End Sub
 Public Property Employee(ByVal ID As Integer) As Employee
   Get
     Dim TheObject As Object
     TheObject = MEmployees.Item(ID)
     Return CType(TheObject, Employee)
   End Get
   Set(ByVal Value As Employee)
     MEmployees.Item(ID) = Value
   End Set
 End Property

End Class Module Test

 Sub Main()
   Dim Employer As New Employer()
   Employer.Employee(1) = New Employee("A", 25000)
   Employer.Employee(2) = New Employee("J", 35000)
   Employer.Employee(3) = New Employee("T", 17000)
   Employer.Employee(4) = New Employee("E", 16500)
   Dim ID As Integer = 3
   Dim Who As Employee
   Who = employer.Employee(ID)
   If Who Is Nothing Then
     Console.WriteLine("Unrecognized ID: {0}", ID)
   Else
     Console.WriteLine("Employee details: {0}", Who)
   End If
 End Sub

End Module</source>

Employee details: T 17000

Throw Exception in Property setting

<source lang="vbnet">Imports System Module Test

 Sub Main()
   
   Dim p as Point = New Point()
   
   Console.WriteLine("(" & p.X & "," & p.Y & ")") 
   
   Try
     p.X = -100
     p.Y = -100
   Catch e as ArgumentOutOfRangeException
     Console.WriteLine(e.Message)
   End Try
   
   Console.WriteLine("(" & p.X & "," & p.Y & ")") 
 End Sub

End Module Public Class Point

 Private yCoord as Integer
 Private xCoord as Integer
 Public Property X as Integer
   Get
     Return xCoord
   End Get
   Set(ByVal Value as Integer)
     If Value < 0 then
       Throw New ArgumentOutOfRangeException("Value","X Coordinate must be greater than 0")
     End If
     xCoord = Value
   End Set
 End Property
 
 Public Property Y as Integer
   Get
     Return(yCoord)
   End Get
   Set(ByVal Value as Integer)
     If Value < 0 then 
       Throw new ArgumentOutOfRangeException("Value","Y Coordinate must be greater than 0")
     End If
     yCoord = Value
   End Set
 End Property

End Class</source>

(0,0)
X Coordinate must be greater than 0
Parameter name: Value
(0,0)

Two properties

<source lang="vbnet">Imports System Imports System.Collections Class EmployeeList

 Private mEmployees As Hashtable
 Private mLevels As Hashtable
 Public Sub New()
   mEmployees = New Hashtable()
   mLevels = New Hashtable()
 End Sub
 Public Default Property Employee(ByVal ID As Integer) As Employee
   Get
     Dim theObject As Object
     theObject = mEmployees(ID)
     Return CType(theObject, Employee)
   End Get
   Set(ByVal Value As Employee)
     mEmployees(ID) = Value
   End Set
 End Property
 Public Property Level(ByVal country As String) As String
   Get
     Dim theObject As Object
     theObject = mLevels(country)
     Return CType(theObject, String)
   End Get
   Set(ByVal Value As String)
     mLevels(country) = Value
   End Set
 End Property

End Class

Class Employee

 Private mName As String
 Private mWage As Double
 Private mID As Integer
 Public Sub New(ByVal name As String, ByVal wage As Double,ByVal id As Integer)
   mName = name
   mWage = wage
   mID = id
 End Sub
 Public Property Name() As String
   Get
     Return mName
   End Get
   Set(ByVal Value As String)
     mName = Value
   End Set
 End Property
 Public ReadOnly Property Wage() As Double
   Get
     Return mWage
   End Get
 End Property
 Public ReadOnly Property ID() As Integer
   Get
     Return mID
   End Get
 End Property
 Public Sub PayRise(ByVal amount As Double)
   mWage += amount
 End Sub
 Public Overrides Function ToString() As String
   Return "[" & mID & "] " & mName & " " & mWage
 End Function

End Class Module DefaultProperty

 Sub Main()
   Dim employer As New EmployeeList()
   employer(1) = New Employee("A", 25, 1)
   employer(2) = New Employee("J", 35, 2)
   employer(3) = New Employee("T", 17, 3)
   employer(4) = New Employee("E", 16, 4)
   employer.Level("AA") = "A"
   employer.Level("BB") = "B"
   employer.Level("CC") = "C"
   employer.Level("DD") = "D"
   employer.Level("EE") = "E"
   employer.Level("FF") = "F"
   Dim country As String
   country = "AA"
   Dim city As String
   city = employer.Level(country)
   If city Is Nothing Then
     Console.WriteLine("No office in {0}", country)
   Else
     Console.WriteLine("Level in {0}: {1}", country, city)
   End If
 End Sub

End Module</source>

Level in AA: A

Use Property to set private data

<source lang="vbnet">Module Module1

   Sub Main()
       Dim TheObject As New TheClass
       Console.WriteLine("ThePublicData holds """ & TheObject.ThePublicData & """")
       Console.WriteLine("TheMethod returns """ & TheObject.TheMethod() & """")
       Console.WriteLine("TheProperty holds """ & TheObject.TheProperty & """")
   End Sub

End Module Class TheClass

   Public ThePublicData = "Hello there!"
   Private TheInternalData As String = "Hello there!"
   Function TheMethod() As String
       Return "Hello there!"
   End Function
   Public Property TheProperty() As String
       Get
           Return TheInternalData
       End Get
       Set(ByVal Value As String)
           TheInternalData = Value
       End Set
   End Property

End Class</source>

ThePublicData holds "Hello there!
TheMethod returns "Hello there!
TheProperty holds "Hello there!